Water Stewardship Information Sources
| ID | 924 |
|---|---|
| Citation | Hume, JMB, Morton, KF, Lofthouse, D, Mackinlay, D, Shortreed, KS, Grout, J and Volk, E. 2003. Evaluation of restoration efforts on the 1996 Upper Adams River sockeye salmon run. Canadian Technical Report on Fisheries and Aquatic Sciences No. 2466 |
| Organization | Fisheries and Oceans |
| URL | http://docs.streamnetlibrary.org/CanadaDFO/cdfo-techrpt_2466.pdf |
| Abstract/Description or Keywords | The Upper Adams River has an estimated 1.25 million m2 of spawning grounds and Adams Lake has the potential to produce 26 million sockeye salmon (Oncorhynchus nerka) smolts but blockages, including a splash dam on the Adams River (1907 to 1922) and a slide at Hell's Gate on the Fraser River in 1913 resulted in the total elimination of the Upper Adams River sockeye salmon stock. In light of the previous abundant run and the unused capacity of the system, a long term effort has been made to rebuild the sockeye run to the Upper Adams River. This included egg and fry transplants from 1949 to 1984 resulting in increasing run sizes every four years (most Adams sockeye mature at age-4) until 1988 (7,000). In 1992 the run was considerably smaller (3,000) and a renewed effort was made to enhance the offspring of the 1992 brood year. Reduced exploitation rates (19%) in 1996 resulted in 25,000 sockeye spawners. Fish culture and fry release programs in 1992 and 1996 used native stock from both the Upper Adams River and nearby Momich River system, releasing fry into the river and after net pen rearing, into the north end of Adams Lake. In 1997, 1.3 million fry were released into the river and lake. In addition to the fry release project, the lake was fertilized in 1997 to promote the lake growth and subsequent survival of sockeye in the lake and marine environments. An average of 3 mg P/m2 /wk and 48 mg N/m2 /wk were added to the lake from May to September, using a "front end" loading regime where the nutrients were added at a higher rate in June than in September. We applied two agricultural fertilizers by boat, ammonium nitrate (28-0-0) and ammonium polyphosphate (10-34-0). Particulate C and P were higher in the fertilized year and the year following than in a reference year 1986. Chlorophyll concentrations were highest in 1997 but macrozooplankton showed no significant difference between years. Our analysis, based on known sockeye escapements, length frequency analysis, and the levels of marine Sr in the otolith cores of juvenile O. nerka, determined that reference year samples were virtually all from lake resident kokanee, making between year size comparisons of trawl caught fall fry invalid. However, migrating smolts from the 1996 brood year were 1 g larger (3.6 g) than smolts from the 1992 brood year, which is expected to result in increase marine survival. Comparisons of adult returns to the Upper Adams River from the 1980 cycle brood years with co-migrating stocks to other nearby rivers, indicates increased abundance due to restoration efforts, although the sample size is insufficient for statistically significant comparisons. restoration, aquatic habitat |
| Information Type | report |
| Regional Watershed | Shuswap |
| Sub-watershed if known | Adams River |
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| Comments | |
| Project status | complete |
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